Walter Breckenridge, Associated PressThe scene of an accident in McCrory, Ark., after an a car crashed into a group of bicyclists from a Massachusetts-based summer camp program on a cross-country trip.

LITTLE ROCK, Ark. — An 18-year-old Massachusetts woman died after she was injured when a car struck a group of bicyclists traveling through Arkansas on a cross-country summer trip, authorities said Thursday.

Merritt Levitan, of Milton, Mass., was one of 13 cyclists traveling from Charleston, S.C., to Santa Monica, Calif., as part of a six-week trip organized by a Williamstown, Mass.-based company called Overland.

Overland and Arkansas State Police said Thursday that Levitan died at the Regional Medical Center at Memphis, Tenn. Nursing supervisor Jackie Smartt said Levitan died Wednesday afternoon.

Levitan and six others were injured in the crash Tuesday afternoon near McCrory, Ark., about 90 miles northeast of Little Rock.

Two people remained hospitalized in stable condition on Thursday, Overland director Jonathan Igoe said.

Prosecutors are considering filing charges against the 21-year-old driver who struck the cyclists, but prosecutor John Bell said no charges had been filed as of Thursday.

Bell has said there wasn't any evidence of alcohol in the driver's bloodstream, but he said authorities were looking into whether anything else, such as a cellphone, was involved in the crash.

Arkansas State Police spokesman Bill Sadler said the agency will send an investigative report to prosecutors once it's complete.

Overland founder and director Tom Costley and his wife, Liz, said in a statement that Levitan died from her injuries.

"Liz and I, and the entire Overland community, are heartsick by this tragic loss," Costley said in a statement. "We extend our deepest condolences to Merritt's family, friends and loved ones."

The cyclists were on their way to Newport, Ark., where they planned to spend the night Tuesday, when the driver struck the group on Arkansas State Highway 17.

Overland said the rest of the trip will be canceled.

"At this point, we believe that this is what needs to be done to allow all involved time to process their thoughts and emotions while surrounded by loved ones," the company said in a statement. "We are working with families to make arrangements for students to return home."

Aiming to jolt the rest of the world to action, President Barack Obama moved ahead Sunday with even tougher greenhouse gas cuts on American power plants, setting up a certain confrontation in the courts with energy producers and Republican-led states.